Check Out Both
You might want to investigate a little more and check out both options, Nicro Fico vs. Garhauer before making your choice. Garhauer has a replacement kit designed for the C-30 that replaces everything, track, traveler, control blocks, etc. If you go the Garhauer route you end up with a flat traveler vs. the old style arched traveler. The flat traveler works better by placing a constant tension on the mainsheet as it's adjusted from side to side. The arched track "hardens up" on the mainsheet as it moves outboard. Check the prices, you may be surprised at how economical the Garhauer upgrade is given the extensiveness and advantages of it.Garhauer also makes a very nice and economical rigid vang.